package huawei.nk;

import java.util.HashSet;
import java.util.Scanner;

/**
 * https://www.nowcoder.com/question/next?pid=710802&qid=26011&tid=52158788
 * 字符串 字符去重
 */
public class NKDul {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNextLine()){
            System.out.println(dul(scanner.nextLine()));
        }
    }

    public static String dul(String s){
        boolean[] data = new boolean[128];
        StringBuilder builder = new StringBuilder();
        for(char c:s.toCharArray()){
            if(!data[c]){
                data[c]=true;
                builder.append(c);
            }
        }
        return builder.toString();
    }
}
